Filter `aws s3 ls` buckets by name

[elgalu]

Instead of listing all buckets it would be convenient to have a configurable filter, e.g.

allowed_buckets = new RegExp('^my-company')

Or some other way, e.g.

blocked_buckets = new RegExp('audit-trail$')

Previously I suggested whitelist/blacklist until: https://tools.ietf.org/id/draft-knodel-terminology-00.html